Flexible Rubber Water Pump Impeller 6303-0001 – 6 Blade Neoprene 51 mm Single Flat Drive – Fits Johnson 09-824P

How to Match This Part

This is a flexible rubber raw water / utility pump impeller. It sits inside the pump housing behind the cover plate and is driven by a single flat on the shaft (a D-shaped bore in the brass insert). It replaces the primary original part number Jabsco 6303-0001, and is also supplied against Jabsco 7273-0001, Johnson 09-824P, JMP 7053-01 and Yanmar 14242-050.

Match this part by checking your engine in this order:
1. Original impeller part number (stamped on the old impeller or listed in the pump section of your parts catalog)
2. Drive type (this listing is a single-flat / D-bore, not a pin drive)
3. Pump model (cast or labelled on the pump body)
4. Engine model code (on the identification plate)

Identify it physically before ordering. This impeller has six vanes moulded in black neoprene around a machined brass insert. JMP 7053-01 is 51 mm diameter, 22 mm width and 8 mm (5/16 in.) bore with a single flat drive. It is not interchangeable with pin-drive 51 × 22 mm impellers such as 653-0001 (12 mm pin) or 18673-0001 (12.7 mm pin), or with the smaller D-slot JMP 7013-01 (12 mm D-slot). JMP 7053-02 is the nitrile / bilge version of a related size, not this listing.

• ✓ Primary OEM: Jabsco 6303-0001
• ✓ Product form: 6-blade neoprene impeller, brass insert, 8 mm single flat drive
• ✓ Fitment: part number, then drive type, then pump model

Part Number Cross-Reference

Use this table to confirm equivalent part numbers. Jabsco 6303-0001-P is the genuine retail kit of 6303-0001. This listing is the impeller only.

Compatible Engine Models

Confirm the original impeller number and the single-flat bore. Yanmar 2GM / 3GM raw-water pumps more often use 104211-42070 or 128990-42200, which are different sizes.

Technical Specifications

Package Contents

This listing is for the impeller only, as shown in the product images. Please refer to the part number cross-reference table to confirm component details.

Cover plate gaskets, O-rings and lubricant are not included. JMP 7053-01K adds O-ring ORG0052 and lubricant. If your service procedure calls for a new cover seal, order it separately against your pump model.

Installation Guide

1. 1 Stop the engine or pump, let it cool, and close the raw water seacock if one is fitted so water cannot enter the boat while the pump is open.
2. 2 Remove the cover plate screws and lift off the cover. Keep the screws and the old gasket together so you can compare the seal size when reassembling.
3. 3 Note the orientation of the flat on the shaft, then grip the brass insert and pull the old impeller straight off. Recover any broken vane pieces from the downstream cooling circuit before continuing.
4. 4 Clean the housing bore and the wear plate, and inspect them for scoring. Apply a marine-grade impeller lubricant, glycerine or soapy water to the bore and the new vanes. Do not use petroleum-based grease, which attacks neoprene.
5. 5 Align the D-shaped bore in the brass insert with the flat on the 8 mm pump shaft, then press the impeller in while turning the shaft in the normal direction of rotation so all six vanes lay over the same way.
6. 6 Refit the cover plate with a serviceable gasket or O-ring, tighten the screws evenly in a crisscross pattern, open the seacock, then start the pump and confirm flow and no leaks at the cover.

Note: Professional installation is recommended to ensure safety and optimal performance.

Troubleshooting & FAQ

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist, even if your model is listed, do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• The impeller is supplied on its own. Cover seals and lubricant must be ordered separately if your service procedure requires them.
• This is an 8 mm single-flat drive. It will not fit a pin-drive pump (653-0001, 18673-0001) or the 12 mm D-slot JMP 7013-01.
• Never run the pump dry. Even a few seconds without water will damage the neoprene vanes.
• Professional installation is recommended to ensure safety and optimal performance.

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